[Crash-utility] [PATCH 1/2] X86 64: fix for crash session loading failure
Kernel commit 223b5e57d0d5 ("mm/execmem, arch: convert remaining
overrides of module_alloc to execmem") makes crash session loading
failure as below:
# ./crash -s
crash: seek error: kernel virtual address: ffffffff826bb418 type:
"page_offset_base"
For X86 64 architecture, currently crash will search for symbol
"module_load_offset" to determine if the KASLR is enabled, and go
into the relevant code block. But the symbols "module_load_offset"
has been removed since Linux v6.10-rc1, which caused the current
failure.
And this issue can occur with live debugging and core dump file
debugging.
Let's check the symbol "kaslr_regions" instead of
"module_load_offset"
to fix it.
Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com>
---
symbols.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/symbols.c b/symbols.c
index b7627a83587a..1cdf21d86d69 100644
--- a/symbols.c
+++ b/symbols.c
@@ -619,9 +619,9 @@ strip_symbol_end(const char *name, char *buf)
* or in /proc/kallsyms on a live system.
*
* Setting KASLR_CHECK will trigger a search for "module_load_offset"
- * during the initial symbol sort operation, and if found, will
- * set (RELOC_AUTO|KASLR). On live systems, the search is done
- * here by checking /proc/kallsyms.
+ * or "kaslr_regions" during the initial symbol sort operation, and
+ * if found, will set (RELOC_AUTO|KASLR). On live systems, the search
+ * is done here by checking /proc/kallsyms.
*/
static void
kaslr_init(void)
@@ -646,7 +646,8 @@ kaslr_init(void)
st->_stext_vmlinux = UNINITIALIZED;
if (ACTIVE() && /* Linux 3.15 */
- (symbol_value_from_proc_kallsyms("module_load_offset") != BADVAL)) {
+ ((symbol_value_from_proc_kallsyms("kaslr_regions") != BADVAL) ||
+ (symbol_value_from_proc_kallsyms("module_load_offset") != BADVAL))) {
kt->flags2 |= (RELOC_AUTO|KASLR);
st->_stext_vmlinux = UNINITIALIZED;
}
@@ -14247,7 +14248,9 @@ numeric_forward(const void *P_x, const void *P_y)
st->_stext_vmlinux = valueof(y);
}
if (kt->flags2 & KASLR_CHECK) {
- if (STREQ(x->name, "module_load_offset") ||
+ if (STREQ(x->name, "kaslr_regions") ||
+ STREQ(y->name, "kaslr_regions") ||
+ STREQ(x->name, "module_load_offset") ||
STREQ(y->name, "module_load_offset")) {
kt->flags2 &= ~KASLR_CHECK;
kt->flags2 |= (RELOC_AUTO|KASLR);
--
2.45.1